Disposable paper plates and the like are generally either pressed paperboard containers or are pulp molded. Pulp molded articles, after drying, are strong and rigid but generally have rough surface characteristics. They are not usually coated and are susceptible to penetration by water, oil and other liquids. Pressed paperboard containers, on the other hand, can be decorated and coated with a liquid-resistant coating before being pressed by the forming dies into the desired shape. General background with respect to pressed paperboard containers is seen in U.S. Pat. No. 4,606,496 entitled “Rigid Paperboard Container” of R. P. Marx et al.; U.S. Pat. No. 4,609,140 entitled “Rigid Paperboard Container and Method and Apparatus for Producing Same” of G. J. Van Handel et al.; U.S. Pat. No. 4,721,499 entitled “Method of Producing a Rigid Paperboard Container” of R. P. Marx et al.; U.S. Pat. No. 4,721,500 entitled “Method of Forming a Rigid Paper-Board Container” of G. J. Van Handel et al.; and U.S. Pat. No. 5,203,491 entitled “Bake-In Press-Formed Container” of R. P. Marx et al. Equipment and methods for making paperboard containers are also disclosed in U.S. Pat. No. 4,781,566 entitled “Apparatus and Related Method for Aligning Irregular Blanks Relative to a Die Half” of A. F. Rossi et al.; U.S. Pat. No. 4,832,676 entitled “Method and Apparatus for Forming Paperboard Containers” of A. D. Johns et al.; and U.S. Pat. No. 5,249,946 entitled “Plate Forming Die Set” of R. P. Marx et al. The forming section may typically include a plurality of reciprocating upper die halves opposing, in facing relationship, a plurality of lower die halves. The upper die halves are mounted for reciprocating movement in a direction that is oblique or inclined with respect to the vertical plane. The paperboard blanks, after cutting, are gravity fed to the inclined lower die halves in the forming section. The construction of the die halves and the equipment on which they are mounted may be substantially conventional; for example, as utilized on presses manufactured by the Peerless Manufacturing Company. Optionally included are hydraulic controls. See U.S. Pat. No. 4,588,539 to Rossi et al. For paperboard plate stock of conventional thicknesses i.e. in the range of from about 0.010 to about 0.040 inches, it is preferred that the spacing between the upper die surface and the lower die surface is as taught in U.S. Pat. Nos. 4,721,499 and 4,721,500. Note also the following patents of general interest with respect to forming paperboard containers: U.S. Pat. No. 6,527,687 to Fortney et al. which discloses a cut-in-place forming system with a draw ring and so forth. See Cols. 6-8; U.S. Pat. No. 3,305,434 to Bernier et al. which discloses a paperboard forming apparatus; U.S. Pat. No. 2,832,522 to Schlanger which discloses another paperboard forming apparatus; U.S. Pat. No. 2,595,046 to Amberg discloses still yet another paperboard forming apparatus.
As to further methods of aligning articles in a manufacturing process, see U.S. Pat. No. 5,129,874 to Hayes, III et al. and U.S. Pat. No. 4,150,936 to Shioi et al.
As to air assist in pressware and related apparatus, see U.S. Pat. No. 4,755,128 to Alexander et al.; U.S. Pat. No. 1,793,089 to Heyes; U.S. Pat. No. 5,693,346 to Dull et al.; U.S. Pat. No. 5,364,583 to Hayashi; and U.S. Pat. No. 2,332,937 to Schmidberger.
Despite many advances over the years in equipment for making pressware from paperboard, manufacturing issues remain. For one, it is desirable to more speedily and reliably supply blanks to pressware die sets for pressing into containers. For another, if paperboard blanks are not suitably positioned “on center” in the forming dies then “off center” and potentially unusable product results. Still yet another continuing issue with respect to pressing operations is the ability to reliably remove formed product from the pressing die because of the short cycle times associated with efficient operation of the machinery. In commercial operations it is desirable to operate a die set at over 50 pressings per minute or so in many cases.